Preferential looking paradigms have been used for almost 50 years to study detection and discrimination of stimuli, categorization, memory, concept formation, and individual differences in infant cognition. Yet, relatively little is known about the nature of the representations which mediate novelty preferences. The general aim of this research is to investigate the neural correlates of novelty preferences during the first year of life in order to elucidate the nature of the representation reflected in an infant's differential attention to a novel stimulus. To accomplish this goal, two experiments are proposed. Experiment 1 will employ a cross-sectional design in order to allow the evaluation of differences in infant electroencephalogram (EEG) and event-related potentials (ERPs) which predict novelty preferences across the first year of life. One goal of this research is to evaluate infant novelty preferences against an adult model of dissociable memory systems. In order to investigate this, the effect of retention interval on infant memory will be assessed by two different tasks: preferential looking and priming. ERPs will be recorded while infants participate in these tasks to assess the extent to which different neural circuits may dissociate performance on the tasks, whether there is a difference in the pattern of brain activity which predicts immediate vs delayed recognition memory, and whether there is a difference in the pattern of brain activity during familiarization across the first year of life. Experiment 2 will investigate the effect of experience on novelty preferences in infancy. This will be accomplished b manipulating infants' experience with a particular class of stimuli, and testing infants before and after this experience. The goal of this study are to assess whether experience with a particular class of stimuli effects performance on preferential looking task whether this experience effects brain re-organization of memory systems with respect to the stimuli, and whether such reorganization, if it is found, persists over time even when the stimuli are removed from the environment.